In order to deliver two or more media data containing video data, audio data, etc. by way of a network and to present delivered media data faithfully according to a scenario written in XML (extensible markup language) or the like which is a description language, there is a necessity to bring the two or more media data into synchronization with one another. As a method of bringing two or more media data into synchronization with one another, JP,2003-9120, A discloses a delivery of two or more media data while dynamically carrying out frame skipping, image quality degradation or the like according to the conditions of the network.
FIG. 1 is a diagram explaining a media delivery system disclosed in the above-mentioned publication before examination. Servers Sa, Sb, and Sc each of which delivers media data are connected with a terminal device c which presents media data by way of a very thin channel, a thin channel, and a thick channel of a network 1, respectively. For example, while media data are simultaneously delivered from the servers Sa, Sb, and Sc, the server Sa connected to the very thin channel delivers media data in which frame skipping or image quality degradation is carried out so that the terminal device c can provide a synchronous presentation of the media data simultaneously delivered from the servers Sa, Sb, and Sc according to a scenario written in XML or the like.
A problem with the related art media delivering apparatus constructed as mentioned above is that since the receiving capability of the media receiving apparatus is not taken into consideration at the time of creating the scenario written in XML, there are cases where the scenario written in XML description cannot be executed depending on the receiving capability of the media receiving apparatus, that is, there is a possibility that unpresentable media data are delivered to the media receiving apparatus. Furthermore, there is a possibility that depending on the communication capability of the network, it takes time for the media receiving apparatus to adapt to a synchronous presentation of the two or more media data delivered thereto, and therefore a presentation of the two or more media data cannot be normally provided by the media receiving apparatus in the meantime. Another problem is thus that the media delivering apparatus cannot generate a scenario written in XML according to conditions at the time of delivery of the scenario, and the media receiving apparatus cannot normally present the two or more media data.
The present invention is made in order to solve the above-mentioned problems, and it is therefore an object of the present invention to provide a media delivering apparatus which generates metadata for delivering media data in consideration of the receiving capability of a media receiving apparatus and the communication capability of a network so that the media receiving apparatus can present the media data normally.
It is another object of the present invention to provide a media receiving apparatus which can present media data normally based on metadata delivered from a media delivering apparatus.